Biophotonics, Internet Invited Lecture


Sean Kirkpatrick, Michigan Technological University, USA

Discussion Live Chat Presentation (1.28 Mb)


Optical phase singularities, alternatively known as optical vortices or wavefront dislocations, are locations in a scattered optical field where the intensity of the field is exactly zero and the phase is undefined. The number density, lifetime, and other statistics of these singularities offer versatile methods for assessing motion, flow, and dynamics in biological tissues and structures. In this presentation, I will present our method for locating phase singularities in dynamic speckle patterns that is based on identifying points where the path integral of the phase gradient over a closed four-pixel loop is non-zero. The concept of ‘vortex path length’ will be introduced and it will be shown how the dynamics of the scattering medium influence the spatio-temporal vortex behavior. Finally the relationship between the correlation behavior of dynamic speckle fields relates to the correlation behavior of corresponding vortex fields.

Representing author


Dr. Sean J Kirkpatrick

Michigan Technological University, Chair & Professor of Biomedical Engineering
Houghton, MI, USA

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